The in vitro synthesis of the J, P, and Q proteins (histidine transport components) will be attempted. The synthesis of the periplasmic J protein as a precursor will be investigated. The properties of the in vitro synthesized P protein will be studied. Interaction between the J and the P proteins will be studied; cross-linking experiments will also be performed for this purpose. The Q protein will be identified by a variety of methods. The interaction of the LAO protein with P and its competition with J will be analyzed. The regulation of histidine transport by nitrogen starvation will be studied. The involvement of other proteins, besides the J and the LAO, in an interaction with P will be investigated. Elucidation of the nature of the altered J protein with a defection interaction site will be completed. More mutants of this type will be isolated and studied. Reconstitution with wild-type and mutant J and P proteins will be attempted. Clones carrying fragments of the histidine transport operon will be sequenced in order to detect any interesting characteristics of the genes of these exported proteins and their regulation.